There are a variety of locking or latching designs or systems in the electrical connector art for positively locking a first connector to a second connector or other mating structure. In some latching systems, it is desirable to have high unmating forces between the connectors, to prevent inadvertent disconnection of the mating structures, however, at the same time, it is undesirable to have excessive mating forces which might damage the connectors upon coupling them. To address these seemingly conflicting force requirements, some connector latching systems have incorporated manually actuatable latches wherein the latches of one connector are in a locked and undeflected state when mated to a second connector, and yet the connectors are easily unmated upon manual deflection or depression of the latches by a user. Such latches often are molded integrally with one of the connector housings, such as on the sides of the housing. This type of latching system has its disadvantages, however. Because of the stress levels on the latches during repeated actuation, and because of the tendency of users to unmate or attempt to unmate the connectors without actuating the latches, plastic latches are often susceptible to damage or breakage. Therefore, secondary metal latches often are used to increase the latch life and provide integrity to the latching structure. A manually actuatable portion of the metal latch may be overmolded or otherwise covered in plastic to minimize local stresses on the metal latch as well as to locate the latch within a connector housing.
There are various connector applications wherein the above latching systems, including metal latching systems, have encountered problems. For instance, in the case of cable assemblies incorporating input/output (I/O) connectors which attach to one end of an IC or memory card to couple an underlying computer (e.g. a lap top or a notebook computer) to an external device (such as a modem or facsimile), the I/O cable assembly may be transported and used in a non-conventional or non-office type environment. Under such circumstances, it is desirable to have a positive latching system between the cable assembly I/O connector and the mating connector on the IC card for various reasons. First, the lock minimizes, and may even prevent, inadvertent disconnection of the two connectors, which disconnection might interfere with data transfer or signal processing or the like. Second, the lock may provide an audible click, tactile feedback or other sensory indication to alert a user that a complete connection has been made in order to alert a user that a program or particular data-reading function can commence.
However, given the propensity of users to attempt to hastily remove the cable assembly from the IC card without actuating the latch structure, and given the fact that various computers currently used are portable and therefore operate in unconventional environments, it also is desirable to have a connector latching structure which permits disengagement of the connectors without manually actuating or releasing the latching structure. In other words, if a user hastily pulls on or trips over the cable assembly, and the connector latching structure does not release, the computer can fall to the floor or otherwise be damaged.
From the foregoing, it can be understood that if a connector latching structure can only be disconnected by manual actuation of the latches, the connector latching structure is prone to be damaged, broken or rendered ineffective, or the computer or IC card may be damaged or broken, which may even cause injury to a user. Accordingly, there is a need for a connector latching structure which allows minimal mating and unmating forces if desired (i.e. actuated), but which also permits unmating of the connectors with a given acceptable force greater than the minimal force without actuation of the connector latching structure. This invention is directed to a locking system that meets those requirements and solves the problems outlined above.